I can't login to LFS world anymore. I can see my online stats as guest but I can't login. I'm using the right password, there is also no text that something is wrong. After the click on login I'm back on the start page again. Can anyone help me?

Can you try login in using a private/incognito window? (or a different browser for that matter)

That way you would discard an issue with your browser's cookies.